Connection of underwater lines

ABSTRACT

Underwater flow lines, control lines and electrical conduits are connected to mating hubs on an underwater manifold center or other production unit by utilizing hydraulically powered means for pulling the lines toward the mating hubs and aligning them therewith, lock-down means actuated from the surface being utilized to lock the lines in axial alignment with the hubs, and a seal member being lowered from the surface and inserted between the facing hubs, with a split clamp being used to draw the hubs into sealing engagement with the seal means.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to the remote connection of underwater flow linesand other conduits to a production unit such as an underwater manifoldcenter, without the use of divers.

2. Description of the Prior Art

The original offshore oil and gas wells were completed on platformsresting on the ocean bottom, or were completed on the bottom and surfaceproduction facilities installed on such a platform. Oil and gas fromsuch platforms was either collected by tankers or by flow lines laid onthe bottom. To the extent that underwater work was required, it wasperformed by divers, by submarines, or by simple manipulations from thesurface.

More recently it has become necessary to drill oil and gas wells inwater which is too deep, or too dangerous, for convenient underwateroperations by divers, or for use of platforms standing on the bottom. Ithas thus become necessary to devise methods of completing oil and gaswells on the bottom, and connecting them up with underwater pipe lines,hydraulic control lines and electrical cables for operation ofunderwater equipment, without the use of divers or any permanent surfacestructure adjacent the underwater well. Various devices have heretoforebeen proposed for connecting such underwater flow lines, etc., as shownfor example in U.S. Pat. No. 3,968,838 to Baugh, No. 4,019,334 toSinclair, et al, and No. 4,086,778 to Latham, et al. A betterunderstanding of the problems presented may be obtained by reference tothe January 1978 issue of Offshore Services magazine, published bySpearhead Publications Limited, at pages 26 to 51.

SUMMARY OF THE INVENTION

The present invention provides a means and method for connectingunderwater lines, including flow lines, control lines, and electricalcables from a remote location on the surface of the water, providing asealed connection between such lines, by means of a tool which islowered from the surface and which is fully recovered to the surfaceafter the connection is made. The apparatus of this invention allows thefurther use of the same tool for later breaking the connection andreplacing or modifying the sealing elements if this becomes necessary.

Apparatus which has previously been designed for this purpose hasrequired the application of high bending loads to the guide posts of theunderwater base units upon which production units are supported. Inaddition, such apparatus has generally included hydraulic cylinders andother tools which are left on the bottom after the connection is made,thereby increasing the cost of operation since such tools cannot be usedagain. Previous designs also have failed to provide for re-entry toretrieve seal members or hubs which have previously been connected.

The apparatus and method of the present invention overcomes thesedeficiencies of the prior art, providing means for absorbing horizontalreaction to forces which result from pulling hubs together to connectthem. A connector tool is provided to lower the seal unit to thelocation where the connection is to be made, to pull the facing hubsinto sealing engagement with the seal unit, and to secure the hubs insealing engagement with the seal unit. The entire connector tool canthen be removed to the surface. The design is such that the connectortool can also be returned to the subsea location and the processreversed so as to retrieve the seal unit and replace it with anidentical or a different seal unit. The connector tool is entirelyretrievable, no portion of it being required to remain on the bottom.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate the presently preferred embodimentof the invention. However, since the invention has never actually beenconstructed or used, it is anticipated that further improvements in thedesign of individual elements may take place before final use of theinvention.

FIG. 1 is a view of a section of the sea depicting the vessels used inperforming the process of this invention together with a schematicrepresentation of the apparatus of this invention;

FIG. 1A is an elevational view of an underwater production unit with theconnector tool of this invention being removed to the surface afterfinal clamp-up of the inboard hub and the outboard hub on the basestructure of the underwater production unit;

FIG. 2 is a perspective view of the base structure of the apparatus ofthis invention, showing an inboard hub for connection to a flow line;

FIG. 3 is a perspective view of another embodiment showing hubs forconnection of hydraulic and electrical lines;

FIG. 3A is a partial elevational view of an underwater production unitwith the pull-in tool used to pull the outboard hub into position beingshown as being lowered down to the underwater production base;

FIG. 4 is a perspective view of the pull-in tool used to pull a flowline into position to be connected;

FIG. 5 is an elevational view of the tool of FIG. 4;

FIG. 6 is an elevational view of the end of the flow line hub with apull-in adapter thereon which enables it to be pulled into position forconnection;

FIG. 7 is a plan view of the end of hydraulic and electric line hubswith a pull-in adapter thereon;

FIG. 8 is an elevational view, partly in section, showing the pulling ofthe pull-in adapter by the pull-in tool;

FIG. 9 is a sectional view of a latch secured to a bullplug used on oneembodiment of pull-in adapter;

FIG. 10 is a plan view of the apparatus in FIG. 8;

FIG. 11 is an elevational view, partly in section, of a flow line huband connected pull-in adapter;

FIGS. 12 to 15 inclusive are elevational views similar to FIG. 11,showing successive stages of operation;

FIG. 16 is an elevational view of the connector tool of this invention,shown in position just before engaging the hubs to be connected;

FIGS. 17, 18 and 19 are elevational views of the apparatus of FIG. 16,shown at successive stages of operation;

FIG. 20 is an elevational view, partially in section, of the portion ofthe pull-in tool used to operate locking mechanism between the pull-inadapter, the hub and the base;

FIG. 21 is a plan view, partially in section, of the apparatus of FIG.20;

FIG. 22 is an elevational view of the connector tool shown in FIGS. 16to 19, taken at right angles to FIG. 16;

FIG. 23 is a vertical sectional view of a pin mechanism forming a partof the tool of FIG. 22;

FIG. 24 is an elevational view of a protective cover used on the hubsaccording to the invention;

FIG. 25 is a vertical sectional view of the protective cover of FIG. 24,taken at line 25--25 of FIG. 24;

FIG. 26 is a sectional view taken at line 26--26 of FIG. 24; and

FIG. 27 is a sectional view taken at line 27--27 of FIG. 24.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring first to FIG. 1 of the drawing there is illustrated a floatingvessel A having a drill pipe 10 and various guidlines 11 extendingdownwardly therefrom to an underwater production unit 12. Another vesselB constitutes a pipe laying barge such as is well known in the art forlaying underwater pipe lines for oil and gas, having depending therefroma flowline 13 which is fitted at its end near the underwater productionunit 12 with a pull-in adapter 14. The underwater production unit andthe pull-in adapter 14 are shown resting on the subsea bottom 15.

In FIG. 2 of the drawing there is illustrated a portion of an underwatermanifold center 16 which constitutes a production unit 17, only a partof which is shown, and a base 18, which may be provided for gatheringoil or gas produced from one or a number of wells and for transferringthe produced oil or gas to a flow line. As shown in FIG. 2, a productionunit such as a christmas tree, has been landed on the base 18, beingguided into position thereon by engagement of guide tubes 20 with guideposts 22. An inboard hub 24 is mounted on the production unit, beinglongitudinally slidably supported between the guide tubes 20 by means ofa bearing housing 23 mounted on bars 23a. The hub includes a sealingface 24a, and a cylindrical bearing portion 24b, with an intermediatecollar 24c. The bearing portion is slidably received within a bearing(not shown) in bearing housing 23, and is connected to flowline loops25, 27. The outboard portion of the base constitutes a porch 26 havingan outwardly and downwardly sloping ramp 27 which extends downwardlyover the edge of the manifold center adjacent to the subsea bottom. Thebase is also provided with four upwardly extending reaction posts 28,30, and with lock down holes 32 which are adapted to receive lock downposts 34 (see FIG. 11) as will be later explained.

Another porch 26' shown mounted adjacent porch 26 may be used, forexample, for connecting lines such as hydraulic control lines andelectrical cables. Although the procedures and apparatus describedherein are suitable for all of such connections, this description willbe primarily in terms of connection of flow lines. Such modifications asmay be necessary to connect other types of lines will be apparent tothose skilled in the art. FIG. 3, however, shows a connection base 18'on which are mounted means for connection of both electrical cables atcoupling 36 and hydraulic control lines at coupling 38.

In FIG. 4 of the drawing a pull-in tool 39 has been landed on the porch26. As shown, it has been guided into place by means of the engagementof guide tubes 40 with the guide posts 22. Legs 42, 44 have also engagedthe reaction posts 28, 30 respectively. The legs 44 are connected to theguide tubes 40 by means of structural members 46. The upper ends of legs42 are connected together by means of a U-shaped guard 48 which extendsoutboard to protect a push down bar 50 which extends between the guideposts 42 and is vertically movable relative thereto. A hub lock-downmechanism 62, including lockdown pins 64, is mounted on the pushdownbar.

The pull-in tool 39 is locked down on the base by means of a hydrauliccylinder 41 mounted on guide tube 40 in such a position that its pistonrod 43 can pass through aligned holes in leg 44 and reaction post 30.

A cross member 56 extends between the structural members 46 and hassupported thereon the pulling apparatus 58, including a bull nose latch60. As seen in FIG. 4 the bull nose latch is positioned above, andextends outboard from, the inboard hub 24.

On the inboard side of the pull-in tool, and in line with the bull noselatch 60, there is mounted a hydraulic cable puller 66 to which thedrill pipe 10 is connected. A pulling cable 68 passes through the drillpipe, through other mechanism to be discussed later, and out the bullnose latch 60.

The hydraulic cable puller may, for example, comprise jaws to grip thecable, the jaws being driven by a hydraulic cylinder, and being releasedafter each pulling stroke. Alternatively, the cable may be pulled by awinch at the surface and the hydraulic cable puller omitted.

FIG. 5 illustrates the run-in tool as it may be set up for connection ofelectrical cable or control lines. Although shown centered, in thisarrangement the bull nose latch 60 and the cable puller 66 may be offcenter. The push down bar 50 is provided with two lock down mechanisms62.

FIG. 6 depicts the end of the flow lines 13 and the pull-in adapter 14connected thereto. The flow lines terminate in a lock down structure 70,which is permanently fastened to the ends of the flow lines 13 and tothe flow line hub 72. The flow line hub is carried within a protectivecage 74, comprising a box like structure which may be covered on thebottom by a hinged cover, and plate 76 is provided with an alignmentslot 77 in its upper edge. A bull nose 78 extends at right angles to theplate 76. The end of wire line 68 is connected to this bull nose. Thepull-in adapter 14, comprising plate 76, with the bull nose 78, the cage74 and a locking sleeve 80 attached thereto, are removably connected tothe lock down structure 70 and hub 72 by means of a locking pin 82.

Hub 72 comprises a sealing face 72a and a collar 72b intermediate thesealing face and the lock down structure 70. A protective cover 200 isreleasably attached to the hub.

As seen in FIG. 11, the lockdown structure 70 includes a pair of lockholes 71, each of which has a locking recess 73 adjacent its lower endand a stop shoulder 69 intermediate the recess and the upper end. Alocking sleeve 75 having an enlarged upper end 77 is received withineach lock hole 71. The sleeve is longitudinally slotted at its lower endto form a plurality of resilient fingers 79 which are enlarged at 81 forengagement in the recess 73.

Locking sleeve 80 also is slotted to form downwardly extending resilientfingers 79 having enlargements 81 for engagement in recesses 73. A lockpin 82, having a head 83 and a collar 85, fits in the base of eachsleeve 80, the lower end preventing movement of the fingers 79 out ofthe recesses 73, and thereby securing the pull-in adapter to the hubassembly, including the lockdown structure.

FIGS. 24-27 depict one form of hub cover 200 which may be used. Thiscover comprises a body 201 having a U-shaped cavity 202 thereinconfigured to fit the circumference of the hub. A protective plate 204received within the cavity is made of a relatively soft, preferablyplastic material, such as Delin, to engage the sealing face of the huband prevent damage to it. The plate 204 is fastened to the body as bymeans of fastening assemblies 206, each comprising a rod 208 and a screw210. The cover 204 is biased into engagement with the face of the hub bymeans of a spring 212.

The cover body is held in place on the hub by means of a pair of detents214 each of which is carried in a tube 216. The tube 216 is secured inposition so that the detent engages the hub recess by means of a rod 218which extends out the upper end of the cover. Rods 218 are attached to atrigger plate 220. The rods are held in their uppermost position asshown in the drawing, by means of shear pins 222, each of which engagesa recess 224 on one of the rods. The rods are also provided with anotherrecess 226 which, in the position shown in FIGS. 24 and 25, is locatedjust above the detent. The detent tube 216 has a groove 228 in one sidewhich receives the body of the rod 218, so that the rod holds the detentin the hub recess.

Upon the application of downward force to the trigger 220 the rods 218move downwardly, shearing the shear pins, until the recess 226 isopposite the detent tube 216. The application of additional downwardforce causes the tapered end of the detent 214 to be biased laterallyout of the hub face recess. The hub cover therefore drops off of thehub.

The structure of posts 42 and push down bar 50 are shown in detail inFIGS. 20 and 21. As shown there, each post contains a part of telescopichydraulic cylinders 150, 152, one of which is mounted at the bottom ofthe post with its rod extending upwardly and the other which is mountedat the top of the post with its rod extended downwardly. The cylindersare provided with hydraulic connections (not shown) for application ofpower to cause cylinder 150 to push upwardly and cylinder 152 to pushdownwardly. Both piston rods are connected to a single driven member 154comprising a plate to which blocks 156, 158 are attached. Each block isbored to receive the end of a piston rod and a pin 160 to secure the rodto the block. A sleeve 162 extends upwardly from the block 158 and isprovided with a mounting bracket 164 to which a link 166 is attached.The other end of each link 166 is attached to the push down bar 50.

The push down bar 50 is provided with a pair of lock down pin retainersleeves 168 mounted on a gusset 170 which is positioned substantiallycentrally of the length of the push down bar and rigidly fastenedthereto. Each of the sleeves 168 extends upwardly from the gusset and isprovided with a semi-cylindrical window 172 positioned to receive a fork174 which is attached to piston rod 176 of a hydraulic cylinder 178which is mounted on the gusset 170.

A similar pair of hydraulic cylinders 180 are mounted on a bottom gussetplate 182 on the push down bar, and similar forks 185 are mounted onrods of these cylinders. These forks are positioned to be extendedthrough windows 276 in lock down pin retainer sleeves 278.

FIG. 7 shows in plan view a pull-in adapter for hydraulic lines 84 andelectric lines 86. A pair of lock down structures 70 are provided, andthe lock down structures are releasably connected, by means of lockingpins 82 and locking sleeves 80 to a plate 76 on which is mounted aprotective cage 74a which provides protection for hubs 72a and 72b. Theplate 76 also has mounted thereon a bull nose 78 to which is attachedthe pulling cable 68.

FIG. 8 shows the use of the pulling cable 68 to pull the pull-in adapter14 up ramp 27 onto the porch 26. In some cases the pull-in adapter andhub assembly may be suspended off the bottom, but the apparatus worksthe same way in either event. The pulling cable extends from the bullnose latch 60, and thence through a universal joint 88, a rotaryactuator 90 and a hydraulic cylinder 92. Passing out the hydrauliccylinder the pulling cable passes over a series of rollers 96 and aplurality of sheaves 97, 98, 99 before leading into the hydraulic cablepuller 66.

The piston rod 94 as well as the piston 240 are bored through the centeras shown at 242 to allow passage of the pulling cable therethrough. Atubular member 244 slidably and sealingly received within the cylinder92 provides a conduit to pass the pulling cable out the end of thecylinder.

A spline gear 246 is mounted on the piston rod 94 and is engaged by arack 248 which is connected for driving a hydraulic cylinder, not shown.This rack, gear and cylinder combination are capable of rotating thepiston rod, and therefore the latch 60, a total of in excess of 360°,i.e. at least 180° in each direction from the central position depictedin the drawings.

FIG. 9 shows one embodiment of the latch 60 with the bull nose 78latched in place. The latch comprises a generally cylindrical housinghaving a back plate 250 and a front opening 252 through which the bullnose may be received. A plurality, preferably three, latch jaws 254 arepivotally mounted at 256 in a position to be swung into engagementbehind the shoulder 258 of the bull nose. Pivoting is obtained by meansof a hydraulic cylinder 260, one of which is provided for each latchjaw. The piston rod 262 of the hydraulic cylinder is pivotallyconnected, as by linkage 264, to the latch jaw 254. The latch housingalso contains an orientation pin 266 which is slidably received within acylindrical hole 268 in the face of the latch. The orientation pin isretained in the hole 268 by means of a lock nut 270 screwed on to theend of a reduced diameter portion 272 of the orientation pin. A spring274 biases the orientation pin to the position shown in the drawing,i.e., with the end of the pin extending beyond the fact of the latch.

FIG. 10 shows a plan view depicting the relative positions of the latch60 and the pull-in adapater 14 assembled on the hub at the point wherebull nose is pulled into the latch. At this point, in the usual case,the flow line and its hub 72 will not be in alignment with the inboardhub. However, the flow line hub will be in approximately its finallocation.

FIG. 16 shows the flow line connector running tool 100 being loweredinto place by means of a drill pipe running string 10. The connectorrunning tool 100 is guided into proper position by means of guide tubes107 which follow guide posts 22 and guide lines 11. The flow lineconnector running tool comprises a support frame having a header 102 anda part of depending vertical frame members 104. One frame member 104 hasmounted thereon a fork 105, and another fork 106 (see FIG. 22) ismounted on a support member 110 which is movable laterally relative tothe frame members 104. A plurality of hydraulic cylinders 108 extendbetween fork 105 and support member 110 which is slideably mounted onrods 112 extending between the frame members 104. Two hydraulic motors113 and gear boxes 114 are mounted for horizontal movement with thehydraulic cylinders. A hexagonal socket 115 is connected for driving bythe output shaft of each gearbox. A flowline connector 116 is suportedbelow the gear boxes through a pair of pins 118.

The flow line connector may be of the type shown in U.S. Pat. No.3,843,168 issued Oct. 22, 1974 on the application of Morrill, et al, andentitled "Clamp Connectors". Such connectors, as seen, for example, inFIG. 16, include a pair of plates 120, 122 attached to a seal plate 124which is carried between the two halves 126, 128 of a clamp. A pair ofcylindrical sleeves 130 extend between the upper plate 120 and the lowerplate 122 and receive therethrough the pins 118 which depend from therunning tool 100. As seen in FIG. 23 each pin 118 is provided near itslower end with a pair of laterally slidable latch members 132 positionedfor engagement by a conical wedge 134 carried on the end of a rod 136,which in turn is fastened to a piston 138. Piston 138 is carried withina cylindrical cavity 140 within the pin, and is biased upwardly by meansof a spring 142. A hydraulic line 144 is provided to conduct hydraulicfluid to and from the cylindrical cavity.

For the sake of simplicity, no attempt has been made to show all thehydraulic lines and connections which are necessary to operate theequipment described, since these are well known in the art. Suchconnections and lines are provided where necessary, and hydraulic hosesare connected before the tools are lowered. These may then be strappedto the drill pipe as each tool is lowered. A suitable control panel, asis also well-known in the art, is provided on vessel A so that the toolsmay be operated, as hereinafter described.

OPERATION

The operation of the apparatus and method of this invention begins withthe establishment of the guide lines 11 between the vessel A and thesubsea production unit 12.

The pull-in tool is tested on vessel A to make sure that it functionsproperly. The flow line bundle is assembled on vessel B and the pull-inadapter 14, the flow line hub assembly, and the protective cover areattached thereto. The necessary hydraulic hoses are attached to thepull-in tool 39, the wire line 68 comprising the pull-in cable isprepared by attaching a retrieval dart on one end and a swivel head onthe other; the retrieval dart is installed in the cable puller 66 andthe swivel head end is installed in the bull nose 78 on vessel B. Theguide lines are then threaded through the guide tubes 40 on the pull-intool, the drill pipe 10 is connected to the hydraulic cable puller 66and the tool is lowered to the bottom. While it is being lowered thepull-in cable is paid out from vessel B, maintaining tension on it toprevent entanglement. As the tool approaches the porch, pressure isapplied to the "release" side of the pull-in tool lock down cylinder 41.The tool is then landed on the porch and pressure is applied to the"lock" side of the lock down cylinder. The drill pipe is then pulledupwardly with a force of, for example, 5,000 pounds over the weight ofthe running string and pull-in tool, the force being sufficient toinsure that the tool is locked to the porch. Pressure is applied tocylinders 150 to insure that the assembly is properly elevated. Thispressure is maintained throughout the pull-in operation. The cableretrieving dart is fished through the drill pipe and pulled to thesurface, paying out pull-in cable from vessel B to compensate. Tensionis maintained on the cable to prevent entanglement. On vessel A the endof the pull-in cable is attached to a winch.

The flow line bundle is then lowered from vessel B toward the seabed,with excess cable being reeled in on vessel A. It is important tocarefully note pull-in loads in order to avoid exceeding the maximumcable capacity. After the flow line bundle has neared or reached theseabed, pulling by means of the cable is continued until the pull-inadapter 14 approaches the ramp 27. Preferably a television camera isused to view the operation to determine when the adapter is in asuitable position. Pulling is continued until the bull nose 78 entersthe bull nose latch 60. This can be monitored by means of the televisioncamera. In addition entry can be identified by the sudden increase inthe load on the pull-in cable. If necessary, water may be pumped downthrough the drill pipe to jet wash the pull-in adapter.

When the bull nose has entered the latch, pressure is applied to the"lock" side of the bull nose latch hydraulic cylinders 260 to cause thejaws 254 of the latch to close around the bull nose. In order to achieveproper radial alignment the rotary actuator 90 is actuated to rotate thelatch in either the clockwise or counterclockwise direction until thebull nose latch orientation pin 266 engages the slot 77 in the pull-inadapter. The rotary actuator is then operated again to rotate thepull-in adapter 14 with the attached flow line hub 72 until it is inproper alignment with the inboard hub 24.

At this point the latch and flow line adapter assembly may, for example,be in the condition shown in FIG. 10, since is is expected that therewill be some misalignment in the usual case. Fluid pressure is thenapplied to the hydraulic cylinder 92, causing the back plate 250 of thelatch 60 to be pulled into engagement with the front plate 280 of therotary actuator 90. When one edge of the plate 250 engages the plate280, additional pulling causes the latch with the attached flow lineadapter to pivot about the contacting edge until the plates are in fullcontact and the outboard flow line hub is axially aligned with theinboard hub.

At this point the various structures are in the positions shown in FIG.11. The push down bar 50 is then lowered by means of the telescopinghydraulic cylinders 150, 152 until the lower ends of the retainersleeves 184 engage the upper ends 77 of the locking sleeves 75. As seenin FIG. 11, the sleeve 184 carries within it a lock pin 186 which issupported therein by means of the fork 185. The lock pin is provided,near its lower end, with a spring loaded latch 188. When the sleeve 184moves into engagement with the upper end of the sleeve 75, as shown inFIG. 12, the lower end of the pin does not extend into the lower reduceddiameter bore 190 of the sleeve 75. Thus downward pressure on the sleeve75 causes the enlarged portions 81 to be biased inwardly from the recess73 so that the sleeve moves downwardly into a recess 192 in the lockdown hole 32 in the porch, as seen in FIG. 12. The forks 174 are thenwithdrawn and the push down bar 50 is elevated until the forks are abovethe top of the pin 186, as seen in FIG. 13. The forks are again extendedinto the sleeve 184 and the push down bar 50 is moved downwardly. Theforks engage the upward end of the pin 186 pushing the pin downwardlyuntil it extends into the lower reduced diameter bore 190. The enlargedends 81 of the fingers 79 are thus held in engagement with recess 192 sothat the lock down structure 70 is locked to the porch 26.

The forks 174 are then withdrawn again, and the push down bar 50 islowered until sleeve 168 rests upon the upper end of locking sleeve 80,as seen in FIG. 14. The hydraulic cylinders 178, 180 are then energizedto move the forks 174 into sleeve 168, engaging the lock pin 82 betweenthe head 83 and the collar 85.

As seen in FIG. 15 the push down bar 50 is then moved upwardly. Themovement of the forks 174 pulls the pin 82 from the sleeve 80, therebyunlocking the sleeve. Hydraulic cylinder 41 (see FIG. 4) is thenretracted to release the pull-in tool from the base, and the entirepull-in tool is raised upwardly by means of the drill pipe 10, therebypulling the sleeve 80 from the lock down structure 70 and removing theprotective cage 74 from its position covering the outboard flow line hub72. The inboard hub 24 and outboard hub 72 are thus left positionedsubstantially in their final positions, each protected by a protectivecover 200.

The flow line connector running tool 100 is then installed on the guidelines 11 and lowered on drill pipe 10, as seen in FIG. 16. As the toolmoves downwardly the forks 105, 106 straddle the hub saddles 192, 194behind the collars 24c and 72b. Upon further downward movement buttons211 engage trigger plates 220, thereby releasing the protective covers200, causing them to drop off the inboard and outboard hubs. The finalposition of the flow line connector running tool is as shown in FIG. 17,with the seal plate 124 between the two hubs. The hydraulic cylinders108 are then energized to pull the two hubs together by force exerted onthe forks 105, 106, as seen in FIG. 18. Since the outboard hub islatched down on the porch, only the inboard hub moves, by slidingthrough bearing housing 23, such movement being absorbed in the flowline loops on the christmas tree.

The two halves of the clamp assembly 116 are then moved together toclamp the facing hubs into sealing engagement with the seal member byrotation of the hexagon socket 115 which is driven by the motors 113 andthe gear box 114.

Hydraulic pressure is then applied to the piston 138 in the pin 118 tothereby release the latch members 132. The entire flow connector runningtool is then hoisted upwardly by means of the drill pipe, as shown inFIG. 19, and may be retrieved to vessel A.

The apparatus of the present invention also provides means forre-entering, disconnecting the hubs, and retrieving or replacing theseal unit, and also for unlocking the flow line hub from the porch andraising it to the surface for repair or replacement, if such should benecessary.

Thus the flow line connector running tool 100 may again be lowered bymeans of the drill pipe, the forks 105 and 106 straddling the hubsaddles 192, 194 behind the collars 24c and 72b. The pins 118 will enterthe sleeves 130 and move downwardly therein until the latch members 132emerge from the bottom. The hex sockets 115 will engage the hexagondrivers of the clamp and the motor 113 may then be energized to open theclamp, thereby releasing the hubs and the seal member. When the runningtool 100 is elevated, the pins 118 will carry the clamp and sealingmember upwardly with the running tool. A new sealing member may then beinstalled in the same manner as heretofore described.

Where it is necessary to repair or replace a flow line hub the pull-intool 39 is lowered with the pull-in adapter 14 in place. Sleeve 80 willenter the lock down structure 70 and engage the recess 73. Cylinder 41is actuated to lock the pull-in tool to the porch. The push down bar 50is lowered to carry the pin 82 into sleeve 80 and thereby lock it to thelock down structure. The forks 174 are actuated to engage pins 18whereby upon upward movement of the push down bar 50 the pins arepulled. The latches 188 engage the lower ends of sleeves 75, pulling thesleeves from the locking holes 71, thereby unlocking the lock downstructure from the porch. The lock down cylinder 41 may then beretracted and the entire pull-in apparatus may be elevated to thesurface, carrying with it the end of the flow line hub. Alternatively,or in addition, a pull-in cable could have been lowered with the pull-inadapter and this cable utilized to assist in the lifting.

Although this invention has been described primarily in terms of theconnection of a flow line to an underwater production unit, the sameapparatus and method may be used for connection of electrical cables andhydraulic control lines, as previously indicated. Such modifications asmay be necessary to achieve such connections will be apparent to thoseskilled in the art.

Various other embodiments and modifications will also be apparent fromthe foregoing description. The invention is therefore not limited to thespecific embodiments disclosed, but extends to every embodiment withinthe scope of the appended claims.

We claim:
 1. Apparatus for anchoring an underwater flowline to anunderwater production unit in alignment with an inboard hub on saidproduction unit, comprisinga lockdown structure attached to the end ofsaid flowline, an outboard hub on the end of said flowline attached tosaid lockdown structure, a bull nose removably attached to saidlock-down structure, and a pull-in tool removably attached to saidproduction unit, said pull-in tool comprisinga latch engageable withsaid bull nose, a pulling cable extending through said latch havig oneend connectable to said bull nose and the other end connected to pullingmeans, an alignment device rigidly and fixedly mounted on said pull-intool and having a central axis parallel to and a predetermined distanceabove the flow axis of the inboard hub, said alignment device includingmeans engageable with said lockdown structure for rotation thereof,without axial movement, about said central axis to position the outboardhub in approximate coaxial alignment with the inboard hub, and meansengageable with said lock-down structure for pivoting said lock-downstructure to vertical alignment with the inboard hub whereby saidoutboard hub is coaxial and in vertical alignment with the inboard hub.2. Apparatus as defined by claim 1, wherein said production unit ismounted on guide posts of a base, and includinga pair of reaction postson said production unit in addition to the guide posts, and means onsaid pull-in tool engageable with said reaction posts to absorb theforce of pulling the flowline into alignment.
 3. Apparatus for anchoringan underwater flowline to an underwater production unit in alignmentwith an inboard hub on said production unit, comprisinga lockdownstructure attached to the end of said flowline, an outboard hub on theend of said flowline attached to sad lockdown structure, a bull noseremovably attached to said lockdown structure, and a pull-in toolremovably attached to said production unit, said pull-in toolcomprisinga latch engageable with said bull nose, a pulling cableextending through said latch having one end connectable to said bullnose and the other end connected to pulling means, means engageable withsaid lockdown structure for rotation thereof, without axial movement,about the axis of the bull nose to position the outboard hub inapproximate alignment with the inboard hub, means engageable with thelockdown structure for pivoting the lockdown structure to alignment withthe inboard hub, and pulling means on said pull-in tool engageable withsaid cable to pull the flowline into alignment.
 4. Apparatus foranchoring an underwater flowline to an underwater production unitmounted on a base in alignment with an inboard hub on said productionunit, comprisinga lockdown structure attached to the end of saidflowline, an outboard hub on the end of said flowline attached to saidlockdown structure, a bull nose removably attached to said lockdownstructure; and a pull-in tool removably attached to said productionunit, said pull-in tool comprisinga latch engageable with said bullnose, a pulling cable extending through said latch having one endconnectable to said bull nose and the other end connected to pullingmeans, means engageable with said lockdown structure for rotationthereof, without axial movement, about the axis of the bull nose toposition the outboard hub in approximate alignment with the inboard hub,means engageable with the lockdown structure for pivoting the lockdownstructure to alignment with the inboard hub, and a pair of lockingsleeves releasably received in said lockdown structure, a correspondingpair of lockdown holes in said production unit base, cooperative lockingmeans on said sleeves and in said holes, and means on said pull-in toolengageable with said sleeves to move them into locking engagement withsaid holes.
 5. Apparatus as defined by claim 4, and includinga bull nosesupport member, a locking sleeve in said support member, a correspondinglockdown hole in said lock down structure, cooperative locking means onsaid sleeve and in said hole, and a locking pin removably receivedwithin said locking sleeve to hold said locking means in lockedposition.
 6. A method for anchoring an outboard hub on an underwaterline in alignment with an inboard hub on an underwater production unitmounted on a base, comprisinglowering a pulling tool to the underwaterbase, pulling the outboard hub by means of a cable to a positionadjacent its final anchored position, rotating said outboard hub,substantially in the absence of axial movement, about an axis parallelto the axis of the inboard hub, to a position at which the axes of thehubs lie in a common vertical plane, applying additional pulling forceon said hub to cause said outboard hub to move into coaxial alignmentand to a predetermined horizontal position with said inboard hub at saidfinal anchored position, and remotely anchoring said outboard hub tosaid base.
 7. A method as defined by claim 6 and includingabsorbing thepulling force on said base in the absence of any substantial pullingforce on said production unit.
 8. A method as defined by claim 6 andincludingraising said pulling tool, lowering a connector tool includinga seal member to the production unit, and connecting the inboard andoutboard hubs.
 9. A method as defined by claim 8 and includingremovingsaid connector tool from said production unit and retrieving it to thesurface.
 10. A method as defined by claim 9 and includingreturning theconnector tool to the production unit, disconnecting the hubs, andretrieving the seal member.
 11. A method as defined by claim 6 andincludingretrieving said pulling tool to the surface, again loweringsaid pulling tool to the underwater base, and remotely releasing theoutboard hub from the base by means of said pulling tool.
 12. Apparatusfor anchoring an underwater flowline hub to an underwater productionunit mounted on a base having guide posts thereon, comprisinga porch onsaid base outboard of said guide posts, at least one reaction post onsaid porch, a pull-in tool, means on said pull-in tool for pulling thehub onto the porch, and means on said pull-in tool for transmittingpulling reaction force to said reaction post.
 13. Apparatus as definedby claim 12 and includinga lock down element on said porch, and lockingmeans on said hub operable by means of said pull-in tool to engage saidlock down element to lock the hub to the base.
 14. Apparatus as definedby claim 12 and includinga ramp extending downwardly and outwardly fromsaid porch.
 15. Apparatus for pulling an underwater flowline,comprising:an underwater base having one or more vertical guideposts; apull-in tool having guide tubes on a frame slidably receiving saidguideposts; a plurality of reaction posts on said base engageable withsaid frame of said pull-in tool for distributing the lateral forces onsaid base and reducing the bending moment on said guideposts caused bythe pulling of the underwater flowline by said pull-in tool, andlockdown means on said frame engaging said reaction posts to lock downsaid pull-in tool on said underwater base.
 16. Apparatus for anchoringan outboard hub on an outboard hub on an underwater flowline to aninboard hub on an underwater base, comprising:an adapter attached to theoutboard hub and the end of the flowline; a bull nose, having ashoulder, removably attached to said adapter and nonaligned with theaxis of the outboard hub; a latch on the base engageable with said bullnose, said latch including a plurality of jaws engageable with saidshoulder on said bull nose, means for aligning said bull nose with saidlatch, a support member on said bull nose having a locking sleeve, acorresponding lockdown hole in said adapter; cooperative locking meanson said sleeve and in said hole; and a locking pin removably receivedwithin said sleeve to hold said locking means in locked position. 17.Apparatus as defined by claim 1 wherein said alignment device furtherincludes means engageable with said lockdown structure for movinghorizontally said lockdown structure to horizontal alignment with theinboard hub.
 18. Apparatus as defined by claims 12 or 15 and including aplurality of reaction posts having different lengths.
 19. Apparatus foranchoring an underwater flowline to an underwater production unit inalignment with an inboard hub on said production unit, comprising:alockdown structure attached to the end of said flowline; an outboard hubon the end of said flowline attached to said lockdown structure; a bullnose removably attached to said lockdown structure; and a pull-in toolremovably attached to said production unit, said pull-in toolcomprisinga latch engageable with said bull nose; a pulling cableextending through said latch having one end connectable to said bullnose and the other end connected to pulling means; an alignment meansincluding vertical alignment means for positioning the flow axis of saidoutboard hub at the same vertical height as the flow axis of the inboardhub; coaxial alignment means for causing the flow axis of said outboardhub to be coaxial with the flow axis of the inboard hub; and horizontalalignment means for positioning said outboard hub a predeterminedhorizontal distance from the inboard hub.
 20. An apparatus according toclaim 19 further including a first connector disposed on said outboardhub and a second connector disposed on the inboard hub; said verticalalignment positioning said first connector and second connector an equaldistance from the flow axis of the inboard hub.
 21. An apparatusaccording to claim 19 wherein said vertical alignment means includesramp means for guiding said outboard hub from the subsea floor up towardthe inboard hub.
 22. An apparatus according to claim 19 wherein saidcoaxial alignment means include joint means for connecting said outboardhub to the inboard hub permitting 360° hinged movement therebetween andbearing means for causing said outboard hub to move into coaxialalignment with the inboard hub.
 23. An apparatus according to claim 19wherein said horizontal alignment means and coaxial alignment meansinclude motor means for moving said outboard hub in a directionhorizontal to the subsea floor and toward the inboard hub.
 24. Anapparatus according to claim 23 wherein said motor means includespistonmeans for moving said outboard hub in the horizontal direction; cylindermeans for housing a portion of said piston means; and hydraulic meansfor moving said portion within said means.
 25. An apparatus according toclaim 19 wherein said vertical alignment means includes arcuate meansfor pivoting said outboard hub through an arc intersecting the flow axisof the inboard hub.
 26. An apparatus according to claim 25 wherein saidarcuate means includes pinion means mounted on pivot means connected atone end with said outboard hub, rack means engaging said pinion means,and hydraulic means for reciprocating said rack means.
 27. An apparatusaccording to claim 24 wherein said vertical alignment means includesturning means for rotating said piston means.
 28. An apparatus accordingto claim 27 wherein said piston means is adapted to reciprocate withrespect to said turning means.
 29. An apparatus according to claim 19further including pulling means disposed on said pull-in tool forpulling said pulling cable.
 30. An apparatus as defined by claim 29wherein said pulling means includes jaws for gripping the cable andbeing released after each pulling stroke.